Cheap card to Crossfire with?

[PandaJohn]

I'm currently running an ATI Radeon HD 5830 made by Sapphire. I'm starting to put together an Eyefinity display, but I would like to boost the performance of my video card if possible.

The 5830 is Crossfire-Ready, but my tower isn't big enough to fit another large card. Is there a small, perhaps outdated video card that I could get to Crossfire and augment my video computing power?

And, for that matter, does Crossfire even work that way? I'm not exactly sure how it works, but from what I've read, it seems like you essentially "meld" the two cards into one. I.e. if my 5830 adds 30X GPU power, and the other card adds 10X GPU power, the computer essentially runs as if it was connected to a card with 40X GPU power.

Any feedback would be very welcome! Thanks in advance!


Edit: some of my system specs:

6GB DDR2 (possibly DDR3, not sure) RAM
1TB 7200rpm Seagate HDD
Sapphire ATI Radeon HD 5830 Crossfire/Eyefinity-ready
Intel Core2 Quad-Core 2.39GHz
Windows 7 64-bit

 

[hunter315]

You have to crossfire within the same GPU family, a 5830 can only CF with a 5830, 5850, 5870, or 5970, you cannot use an older card or a lower powered card to crossfire with it.

 

[PandaJohn]

Ah, so I couldn't, say, link it up to a 4770 or something?

Dang I don't suppose anyone knows of a compact 5000-family ATI card?

 

[hunter315]

No you cannot.

And the families are most specific than just 5xxx, the 5830 can only CF with cards based on a 58xx chip, the 5750 can only CF with other 57xx cards, etc.


here is the chart of what can be CF'ed with what.

 

[PandaJohn]

Best answer selected by PandaJohn.

 

[PandaJohn]

Ahh...looks like I'm out of luck then, unless they come up with a smaller 58xx card...thanks a bunch!